Continued support is requested for the National Magnetic Resonance Facility at Madison (NMRFAM), a shared instrumentation laboratory located in the Biochemistry Department, University of Wisconsin-Madison. NMRFAM contains five modern multinuclear NMR spectrometers with field strengths between 9.4 Tesla (400 MHz) and 17.63 Tesla (750 MHz) equipped for the most demanding multidimensional, multinuclear spectroscopic applications. NMRFAM staff members carry out core research on new approaches to the collection, analysis, and interpretation of NMR data on biological macromolecules. The proposed core research will focus on development of (1) high-pressure multinuclear NMR probes and associated technology, (2) methods for extracting novel information about hydrogen bonding from NMR spectra of proteins, (3) improved methods for quantifying and utilizing magnetization exchange and spin coupling data to determine protein structure and mobility, (4) improved methods for processing and analyzing multidimensional NMR data. Newly developed NMRFAM technology is made available to collaborative and service projects, which are conducted by investigators from a variety of laboratories (on and off campus) who have peer-reviewed funding. The major emphasis of these studies is on the structure and dynamics of biological macromolecules (particularly proteins and enzymes). NMRFAM staff members offer training in data acquisition, processing, and analysis. The products of the laboratory (new instrumentation, techniques, and software) are disseminated to the general scientific community. Funds are needed for equipment upgrades to support the vigorous core, collaborative, and service activities of the facility. Computer graphic workstations are needed to replace obsolete ones. A state-of-the-art, laboratory-scale, multiprocessor compute server is needed to support new initiatives in software development and applications. Research priorities and time allocation at NMRFAM are monitored by its Local and National Advisory Committees. All collaborative and service projects are subject to a uniform schedule of user fees. NMRFAM has a record of serving and catalyzing the research of a diverse user base of graduate students, postdoctoral research associates, staff scientists, principal investigators from 40 laboratories in 15 departments on the University of Wisconsin-Madison Campus and from 35 research groups from around the country. NMRFAM has a proven history for maintaining its instrumentation in top operating condition, for making new NMR technology available to its users, for constructing probes and special circuits, and for creating and distributing software tools for NMR data analysis.